1. Field of the Invention
The present invention relates to image input devices, and more particularly, relates to a device which performs image input of a fingerprint by irradiating a finger placed on a light sensor with light emitted from a light emitter, and detecting light diffused in and transmitted through the finger.
2. Description of the Related Art
Hitherto, as an image input device for fingerprints, for example, there has been a device such as, for example, the device disclosed by Japanese Unexamined Patent Application Publication No. 6-96195. According to the device mentioned above, a fingerprint is detected by placing a finger on a first surface side of a triangular prism; irradiating the finger with light passing through the prism, the light being emitted from light emitter which is disposed at a second surface side of the prism; and detecting light reflected from the finger by a camera or the like disposed at a third surface side of the prism.
Image input devices having the aforementioned configuration adequately perform image inputting. However, since the light emitter, the camera, and the prism are disposed in a three-dimensional way, the aforementioned image input device tends to be large in size, and, as a result, it has been difficult to mount this device on a portable apparatus such as, for example, a notebook type personal computer or a personal digital assistant (PDA).